Although the general template for locomotor limb movements is located within the spinal cord of vertebrates, there is still some debate about the detailed structure of such a centrally contained locomotion generator. One model for such a template, the wave generator hypothesis, states that there is a functional arrangement of motor neurons in the spinal cord of at least lower vertebrates which allows a simple stimulus passing down the cord to stimulate each motor neuron in turn, thus leading to the normal, sterotyped movement of the limbs. The animals used test the model will be a salamander, Ambystoma maculatum, and a teleost fish, Antennarius, sp., which uses its modified pectoral and pelvic fins to walk on coral substrates in marine habitats. The test will consist of the following experiments on these species: (1) examine the total range of movement in the pectoral limb by means of film and dissections; (2) determine the pattern of muscle contractions of all limb muscles by electromyography; (3) map the motor neurons in the pectoral limb-moving segment of the spinal cord using horseradish peroxidase marking; (4) compare the map and muscle sequence patterns.